1. Plural of coesite; a dense, hard form of silicon dioxide (SiO₂) that forms under extremely high pressure and temperature, found in meteorite impact sites and deep crustal rocks.
Usage: technical; geology; mineralogy

Examples

• Coesites were discovered in rocks surrounding the Barringer Meteor Crater in Arizona.
• The presence of coesites in the sample confirmed that the rock had experienced shock metamorphism.
• Geologists use coesites as evidence of ancient meteorite impacts on Earth.
• These rare minerals form only under pressures exceeding 30,000 atmospheres.
• Coesites are denser than ordinary quartz and have a different crystal structure.